Transcription during meiosis of yeast will be characterized using DNA:RNA saturation hybridization. Expression of the genome will be determined at intervals during meiosis in sporulation competent cells and meiotic mutants. Total expression of the yeast genome will be determined using saturation hybridization with polysomal RNA from vegetative and sporulating yeast. Meiotic mutants which appear to be defective in transcription will be be analyzed to determine whether sporulation specific messenger RNA is transcribed.